1. Technical Field
The present invention relates generally to a device and method for sending a message. More particularly, the present invention relates to a device and method for generating a message from sensing signals using a Dual Tone Multiple Frequency (DTMF) signal and transmitting the generated message to a switchboard, wherein the sensing signals are collected by sensors that are connected to an existing telephone that uses Public Switched Telephone Network (PSTN) subscriber lines and power supplied from a switchboard.
2. Description of the Related Art
In order to send a message through an existing PSTN telephone, it is necessary to use a modem capable of Analog-Digital-Analog (A-D-A) conversion in the terminal. This is disadvantageous in that a switch, which is a resource of a switchboard, must be allocated.
Another method is to send a message using a Caller ID (CID) telephone, which displays a calling number. However, this method has a limitation in providing service because the telephone can merely receive text but is not a system for sending text.
Meanwhile, currently, the Internet of Everything (IoE), based on big data, which achieves intelligence using large collections of data, has attracted a lot of attention. Here, data are collected based on sensor nodes having devices capable of communication via Wi-Fi, Zigbee, Ethernet, or the like. There is no problem in using such communication devices in most environments. However, outdoors, or in places having poor communication conditions, the collection of data requires communication devices capable of CDMA, WiBro, LTE, or the like, and these communication devices have problems in that system configuration and installation are costly and in that the provision of an additional power supply or the installation of a battery is necessary for the management thereof.
The Korean Patent Application Publication No. 10-2001-0081143, titled “The Korean letters transmission system using a numeric keypad” discloses a Hangul letter transmission system using a numeric keypad in which Hangul letters are suitably assigned to number buttons from 0 to 9 and function keys on a telephone, a Hangul message signal is directly input using a DTMF signal and converted into a Hangul letter signal, and the converted signal is transmitted to a pager, mobile phone, or other wireless device so as to send a text message. However, Korean Patent Application Publication No. 10-2001-0081143 does not mention a function in which a message is generated from data collected based on sensor nodes and is converted into an encrypted DTMF signal, and the converted signal is transmitted to a switchboard so as to acquire environment information.